Steam-engine



(No Model) W. A. PITT.

STEAM ENGINE.

No. 410,190. Patentd Sept. 3. 1339.

N FEI'ERS, WWI-barium Wnhingtm D. Q

- UNITE STATES PATENT OF ICE.

WILLIAMA. PITT, on eL'ENBRooK, CONNECTICUT.

STEAM-ENGINE.

SPECIFICATION forming part of Letters Patent No. 410,190, datedSeptember 3, 1889.

Application filed October 21, 1887. Serial No. 252,958. (No model.)

To all whom it may concern.-

Be it known that I, VVILLIAM A. PITT, a citizen of the United States,residing at Glenbrook, in the county of Fairfield and State ofConnecticut, have invented certain new and useful Improvements inSteam-Engines, of which the following is a full, clear, and exactspecification, reference being had to the drawings accompanying andforming a part of the same.

My invention relates to improvements in steam-engines; and the object ofmy improvements is to obtain the fullest theoretical duty of the steamand other elastic forces in engines; and this I attain by cutting offthe steam, &c., at initial pressure ata given point in the cylinder, andmaking up for all loss due to the expansion of the same by means ofconstantly-increasing leverage from the start to the finish of a givenstroke of the piston, using two cylinders and two sets of cranks, andintermediate cranks having alternate movements, one from the minimum tothe maximum and the other from the maximum to the minimum, wherebya meanpower is eifected throughout the entire stroke of the engine. Thisobject I attain by the mechanism illustrated in.,the accompanyingdrawings, in which.

Figure 1 is a side elevation of the engine; and Fig. 2 is a top planview of the same, the two views showing clearly the nature of myimprovements.

Let a 0, represent two stean1-cylinders of equal dimensions arrangedside by side.

19 b are the pistons, and e e the respective piston-rods of the same.

61 d are two horizontal shafts suitably mounted in the bed or frame ofthe engine, (the latter not being shown in the drawings;) and p12 arecranks set on the shafts d and d, which are connected by the pitmen g gwith the respective piston-rods e and e.

By reference to Fig. 1 it will be observed that the cranks p and 10 areset on their shafts d and d so as to stand at right angles to eachother. The shafts d and d are arranged in the same vertical line and ata distance from each other in such vertical line equal to the length ofthe stroke of the pis tons in the steam-cylinders a and a.

On the lower shaft dare mounted the cranks at right angles to theintermediate crank,

which is connected with the steam piston-rod. The cranks c c and c c areconnected,.by means of the rods ffand ff with two other sets of cranks71; h and h h on the workingshaft is, which are set opposite to eachother and on the same horizontal plane, as is clearly shown in Fig. 1.The working-shaft k is placed at a distance desirably remote from thetwo steam-cylinders and on a plane about midway between the shafts d andd.

In operation, the steam being admitted into the steam-cylinders, thepistons of the same will be made to travel in opposite directions, andall the cranks will be caused to take an alternate corresponding action,each moving in the direction shown by their respectivearrows in Fig. 1.By reason of the pistons Z) I)? in the cylinders a a being connectedwith the cranks 19 p in a line a little off of the deadcenter, and thecranks h h being connected to the cranks c and c, the most remote pointfrom the same dead-center, shows that the pistons are operating to thegreatest disadvantage at the beginning of the stroke, where a greatertravel in a horizontal plane takes place by the cranks o c and c c inovercoming the resistance at the work-shaft with a much less travelinthe same distance of the said steampistons, but with a continualincreasing power toward the end of the stroke, at which point theoperation is j ust reversed and a much less travel through a horizontaldistance by the cranks c c c c is occasioned by a much greater travelleft to be performed by the steam-pistons, both cranks p 0' being movedonly one fourth of a complete revolution to the'right.

The cranks c and o beiiig twice the length of the cranks h and 72/causes the latter, by means of their pitmen, to be moved the samedistance in the same direction as themselves in making a one-fourth of arevolution; but the cranks h and It will make a one-half revolution inthe same time, and thus equal one stroke of the pistons b b in thesteam-cylinders. The double cranks c c and c c operate the cranks h 71.and h 77.,which are of halflength, and the movement of all these cranksis such that when the steam is pushing and pulling them they will alwaysat some point afiord an increasing length of leverage to v a decreasingsteam-power, and are always made to maintain a reciprocal position toeach other. At the end of the first stroke it will be seen that thepreponderance of leverage is all in favor of the steam and against theresistance to be overcome in the cylinder a, and, vice versa, in thecylinder a. The two cylinderpistons operating their cranks upon theirindividual and intermediate shafts (Z and (1' alternately causes aminimum of power in the one and a maximum of power inthe other to alwaystake place at the same time and at the extreme end of their strokes,thereby effecting a constant force equal to boiler-pressure or meanpower throughout the entire operation of the engine on each and everystroke of the piston. Thus in an engine operating with sixty pounds ofsteam it is possible to out it off at one-eighth of the stroke, or alittle further on in the steam-cylinder, being with my improvement anequivalent to cutting off the steam at a one-quarter of the stroke ofthe piston in a single-acting high-pressure cylinder, and allowing it toexpand in the same cylinder with a result better than that obtained incompound engines with an expenditure of only about one-fourth of thefuel.

My improvements are equally applicable to all classes of engines as wellas air-compressors and vacuum-pumps and other styles of pumps, nomaterial change being necessary to adapt them to all these purposes.

What I claim as new, and desire to secure by Letters Patent, is-

1. In combination, two cylinders with theirpistons and piston-rods, twosets of cranks mounted on independent shafts set in the same verticalplane, each set being placed at right angles to the other, two sets ofcranks set on the same plane on the work-shaft and connected therewith,and two intermediate cranks set on the said independent shafts at rightangles to each other and to the other cranks and connected with thepistons in the respective cylinders, all arranged in the manner and forthe purpose set forth.

2. In an engine, the combination, with two cylinders, their pistons, andpiston-rods, of two shafts set in the same vertical plane, two sets ofcranks placed at right angles to each other on said shafts and connectedwith two cranks mounted on a common shaft set on a plane intermediatebetween the said inde pendent shafts, and two cranks set on theindependent shafts and connected with the piston-rods, as set forth.

3. In combination, the cylinders a a, with pistons and piston-rods b band e e, shafts d d, placed in the same vertical plane, cranks p p,connecting-rods g g, double cranks c c, and double cranks h h, withconnectingrods ffff, as set forth.

4. The combinatiomwith two cylinders and their pistons and piston-rodsand workingshafts, of two shafts placed one above the other andequidistant from the direct line of motion of the engine, two pairs ofcranks set at right angles to each other on said shafts, andintermediate cranks set on the same shafts at right angles to each otherand to the aforesaid cranks, and rods connecting the said cranks withthe piston-rods and workingshaft, as set forth.

5. In an engine, a leverage consisting of double cranks placed onindependent shafts between the piston cross-heads and crankshaft andconnected with double cranks of half-length on the crank-shaft, andcranks interposed between the double cranks and connected with the steampiston-rods, substantially as set forth.

WILLIAM A. PITT.

lN'tnesses:

HERMAN G. Lonw, K. NEWELL.

